1. Field of the Invention
The present invention relates to an etalon device that can be applied to optical systems such as Fabry-Perot type light interferometer, spectrum analyzer etc., and manufacturing method thereof.
2. Description of the Related Art
So far, as a conventional etalon device has been known for example, as shown in Japanese published unexamined patent application Toku Kai Hei 6-241899 etc. FIG. 1 is a schematic view showing an example of composition of the conventional etalon device as shown in Japanese published unexamined patent application Toku Kai Hei 6-241899, etc. FIG. 1A is a longitudinal sectional diagram. FIG. 1B is a sectional diagram along A-A′ of FIG. 1A. As shown in FIG. 1, in this kind of the conventional etalon device, parallel plates 51 and 52 are used as an etalon. The parallel plates 51 and 52, are formed in disk like shape. The parallel plates 51 and 52 are fixed to the inner peripheral surfaces 53a and 54a of holders 53 and 54 by adhesives etc. In the state where each of the optical surfaces of the parallel plates 51 and 52 is faced, one set of subassembly (stationary etalon plate 51, movable etalon plate 52) is positioned through a body 57. A piezo-electric element 56 is incorporated in the body 57. A holder 54 of the movable etalon plate 52 is moved by pressure through the piezo-electric element 56. In this way, it has such structure for changing a separation of surfaces of the parallel plates 51 and 52 which are faced each other.